Invasive Pest Research Articles

Early Detection of Dendroctonus valens Infestation with UAV-Based Thermal and Hyperspectral Images

Dendroctonus valens is one of the main invasive pests in China, causing serious economic and ecological damage. Early detection and control of D. valens can help prevent further outbreaks. Based on unmanned aerial vehicle (UAV) thermal infrared and hyperspectral data, we compared the spectral characteristics of Pinus sylvestris var. mongolica in three states (healthy, early-infested, and dead), and constructed a classification model based on the random forest algorithm using four spectral datasets (reflectance, first derivative, second derivative, and spectral vegetation index) and one temperature parameter dataset. Our results indicated that the spectral differences between healthy and early-infested trees mainly occur in the near-infrared region, with dead trees showing different characteristics. While it was effective to distinguish healthy from early-infested trees using spectral data alone, the addition of a temperature parameter further improved classification accuracy across all datasets. The combination of the spectral vegetation index and temperature parameter achieved the highest accuracy at 93.75%, which is 3.13% higher than using the spectral vegetation index alone. This combination also significantly improved early detection precision by 13.89%. Our findings demonstrated the applicability of UAV-based thermal infrared and combined hyperspectral datasets in monitoring D. valens early-infested trees, providing important technical support for the scientific prevention and control of D. valens.

Image segmentation for pest detection of crop leaves by improvement of regional convolutional neural network

Pest detection is important for crop cultivation. Crop leaf is the main place of pest invasion. Current technologies to detect crop pests have constraints, such as low efficiency, storage demands and limited precision. Image segmentation is a fast and efficient computer-aided detection technology. High resolution image capture solidly supports the crucial processes in discerning pests from images. Study of analytical methods help parse information in the images. In this paper, a regional convolutional neural network (R-CNN) architecture is designed in combination with the radial bisymmetric divergence (RBD) method for enhancing the efficiency of image segmentation. As a special application of RBD, the hierarchical mask (HM) is produced to endorse detection and classification of the leaf-dwelling pests, offering enhanced efficiency and reduced storage requirements. Moreover, to deal with some mislabeled data, a threshold variable is introduced to adjust a fault-tolerant mechanism into HM, to generate a novel threshold-based hierarchical mask (TbHM). Consequently, the hierarchical mask R-CNN (HM-R-CNN) model and the threshold-based hierarchical mask R-CNN (TbHM-R-CNN) model are established to detect various types of healthy and pest-invasive crop leaves to select the regional image features that are rich in pest information. Then simple linear iterative clustering (SLIC) method is incorporation to finish the image segmentation for the classification of pest invasion. The models are tuned and optimized, then validated. The most optimized modeling results are from the TbHM-R-CNN model, with the classification accuracy of 96.2%, the recall of 97.5% and the F1 score of 0.982. Additionally, the HM-R-CNN model observed appreciable results second only to the best model. These results indicate that the proposed methodologies are well-suited for training and testing a dataset of plant diseases, offering heightened accuracy in pest classification. This study revealed that the proposed methods significantly outperform the existing techniques, marking a substantial improvement over current methods.

Role of Gut Bacteria in Enhancing Host Adaptation of Tuta absoluta to Different Host Plants.

The insect gut bacteria play important roles in insect development and growth, such as immune defense, nutrient metabolism, regulating insect adaptations for plants, etc. The Tuta absoluta (Meyrick) is a destructive invasive pest that mainly feeds on solanaceae plants. However, the relationship between gut microflora and host adaption of T. absoluta remains to be known. In this study, we first compared the survival adaptability of T. absoluta feeding with two host plants (tomatoes and potatoes). The T. absoluta completed the generation cycle by feeding on the leaves of both plants. However, the larvae feeding on tomato leaves have shorter larvae durations, longer adult durations, and a greater number of egg production per female. After Single Molecular Real-Time (SMRT) sequencing, according to the LDA Effect Size (LEfSe) analysis, the gut bacterial biomarker of T. absoluta fed on tomato was Enterobacter cloacae and the gut bacterial biomarker of T. absoluta fed on potatoes was Staphylococcus gallinarum and Enterococcus gallinarum. Furthermore, a total of 6 and 7 culturable bacteria were isolated from the guts of tomato- and potato-treated T. absoluta, respectively. However, the isolated strains included bacterial biomarkers E. cloacae and S. gallinarum but not E. gallinarum. In addition, different stains bacterial biomarkers on T. absoluta feeding selection were also studied. E. cloacae enhanced the host preference of the SLTA (T. absoluta of tomato strain) for tomato but had no impact on STTA (T. absoluta of potato strain). S. gallinarum improved the host preference of STTA to a potato but did not affect SLTA. The results showed that the gut bacteria of T. absoluta were affected by exposure to different host plants, and the bacterial biomarkers played an important role in host adaptability. This study not only deepens our understanding of gut bacteria-mediated insect-plant interactions but also provides theoretical support for the development of environmentally friendly and effective agricultural pest control methods.

Multi-omics analysis reveal the fall armyworm Spodoptera frugiperda tolerate high temperature by mediating chitin-related genes

Climate change facilitates the rapid invasion of agricultural pests, threatening global food security. The fall armyworm Spodoptera frugiperda is a highly polyphagous migratory pest tolerant to high temperatures, allowing its proliferation in harsh thermal environments. We aimed to demonstrate mechanisms of its high-temperature tolerance, particularly transcriptional and metabolic regulation, which are poorly understood. To achieve the aim, we examined the impact and mechanism of heat events on S. frugiperda by using multiple approaches: ecological measurements, transcriptomics, metabolomics, RNAi, and CRISPR/Cas9 technology. We observed that several physiological indices (larval survival rate, larval period, pupation rate, pupal weight, eclosion rate, and average fecundity) decreased as the temperature increased, with the 32 °C treatment displaying a significant difference from the control group at 26 °C. Significantly upregulated expression of genes encoding endochitinase and chitin deacetylase was observed in the chitin-binding, extracellular region, and carbohydrate metabolic process GO terms of hemolymph, fat body, and brain, exhibiting a tissue-specific pattern. Significantly enriched pathways (e.g., cutin, suberin, and wax biosynthesis; oxidative phosphorylation and cofactor biosynthesis; diverse amino acid biosynthesis and degradation; carbon metabolism; and energy metabolism), all of which are essential for S. frugiperda larvae to tolerate temperature, were found in metabolites that were expressed differently. Successful RNA interference targeting of the three chitin-related genes reduced gene expression levels and larval survival rate. Knockout of the endochitinase gene by using the CRISPR/Cas9 system significantly reduced the relative gene expression and increased sensitivity to high-temperature exposure. On the basis of our findings, theoretical foundations for understanding the high-temperature tolerance of S. frugiperda populations and latent genetic control strategies were established.

Impact of Aggregation Pheromone Traps on Spatial Distribution of Halyomorpha halys Damage in Apple Orchards.

Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is an invasive pest causing significant damage to tree crops. Our study examined the impact of newly designed aggregation pheromone-baited 'mini-sailboat' (MSB) traps for controlling H. halys and its effect on the spatial distribution of fruit damage. Four replicates of four traps, with a total of 16 MSB traps, were placed along a 1.3 km border of apple orchards, concentrating the traps on one side of the orchards. A fruit damage assessment for incidence and severity was conducted at increasing distances from the orchard border where the traps were placed, encompassing 107 assessment points. Our study showed that deploying MSB traps along the orchard border significantly increased fruit damage within the first 45 m compared to control plots without traps. However, beyond the first 45 m from the border, there was a significant reduction in damage incidence. In the treated plots, 50% of the damage occurred within 26 m of the traps, while in control plots, within 85 m. Shifting the fruit damage pattern means restricting the pests lingering in a narrow strip near the MSB traps, which paves the way for improved techniques to restructure the crop perimeter.

Marking Helicoverpa zea (Lepidoptera: Noctuidae) with fluorophores for use in mark-release-recapture research

Abstract Knowledge of insect dispersal and long-distance migratory flight capacity and patterns represent key factors needed for risk assessment of invasive pest species, insecticide resistance management, and more effective pest control. Having operative tools to both mark and track insect pest movement is therefore critical to achieving such goals. Here, we describe a new procedure for marking Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), one of the most economically important crop pests in the United States. Adult H. zea moths were effectively marked using the liquid fluorophore cartax green, a persistent UV-fluorescent pigment, both directly by topical application and indirectly by briefly submerging pupae in the marking solution prior to adult emergence. Regardless of the application method, the cartax mark was retained on the moths throughout their entire adult lifespan. No mortality differences were observed between cartax green-marked and water-marked (control) moths. Additionally, using rotary flight mills, we found no significant differences in several flight parameters, including total number of flights, flight speeds, flight distances, or flight durations between unmarked and cartax-marked moths. Under laboratory conditions, we did observe the lateral transfer of different colored fluorophores between moths, indicating that undesirable marking could potentially occur. Moreover, we found that not all fluorophores were equally retained on H. zea moths, with cartax green remaining intact on moths longer than did a corresponding magenta fluorophore. The results show that cartax green fluorophore could be a practical marker for H. zea and other holometabolous species targeted for large-scale mark-release-recapture research.

Climate change impacts on worldwide ecological niche and invasive potential of Sternochetus mangiferae.

Present climate studies on invasive species imply that climate change will alter the habitat suitability of invasive pests, especially given the projected rise in average global temperatures by the end of 2100. However, globally, limited information exists on the habitat suitability of the mango stone weevil, Sternochetus mangiferae Fabricius, which impedes the development of early detection and preventive measures. Herein, we used the MaxEnt model to estimate the potential global geographical distribution of S. mangiferae. Our results revealed that thermal conditions played a significant role in explaining the invasion risk of S. mangiferae. Habitat suitability was found in all continents, except Antarctica. Under the present condition, habitat suitability covered 5.67 × 107 km2. For ssp126, habitat suitability will decrease from the 2060s (5.58 × 107 km2) and 2080s (5.57 × 107 km2). Similarly, under ssp585, suitable areas will decrease from 5.62 × 107 to 5.51 × 107 km2 for the 2060s and 2080s, respectively. Our study has estimatedvariability in the habitat suitability of S. mangiferae which establishes a foundation for determining global riskassessment and response plans for the pest. This study also identifies areas where the pest is inherently more vulnerable to the impacts of changing climates and enables forecasting of its potential distribution in a dynamic world. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

First Report of Dalbulus maidis (DeLong and Wolcott) (Hemiptera: Cicadellidae) in Oklahoma.

The corn leafhopper, Dalbulus maidis (DeLong and Wolcott) (Hemiptera: Cicadellidae), is an invasive insect that can cause damage to maize (Zea mays L.) in two ways: by direct feeding and the transmission of several plant pathogens. Dalbulus maidis is an invasive and serious economic pest of maize that has spread from its center of origin in Mexico to the southernmost parts of the United States. Prior to 2024, corn leafhoppers had not been documented in Oklahoma, and their spread northward toward the United States corn belt is of significant concern. Here, we provide the first reports of the insect in maize in several Oklahoma counties. Insect specimens were collected at various commercial and experimental field sites by Oklahoma State University research and extension personnel. The identity of the insect species was validated through morphological and molecular taxonomy. The presence records for the corn leafhopper presented here provide valuable information for future monitoring and management efforts of this economically important pest and disease.

First Report of <i>Tetrastichus howardi</i> (Olliff) and <i>Chelonus formosanus</i> Sonan as parasitoids of fall armyworm, <i>Spodoptera frugiperda</i> (J.E. Smith), in Pakistan

Fall armyworm, Spodoptera frugiperda (J.E. Smith), an invasive agricultural pest, causes substantial economic losses in Pakistan. This study reports the first record of Tetrastichus howardi (Olliff) and Chelonus formosanus Sonan as natural enemies parasitising S. frugiperda within the country. Parasitoids were collected from infested maize fields and identified through morphological analysis. This discovery enhances our understanding of the natural enemy complex associated with S. frugiperda in Pakistan and provides a foundation for investigating their potential as biological control agents. These findings underscore the potential of these parasitoids as components of integrated pest management systems to diminish reliance on chemical insecticides and foster sustainable agricultural practices.

New host plant records of rugose spiralling whitefly, Aleurodicus rugioperculatus Martin (Hymenoptera: Sternorrhyncha: Aleyrodidae) in diverse habitats

The current study focused on assessing the prevalence of invasive whitefly infestation in diverse habitats in the Saurashtra region of Gujarat. The study revealed the presence of Aleurodicus rugioperculatus Martin, specifically in Punica granatum, Ficus religiosa, Ficus benghalensis, Borassus flabellifer, Cordia myxa, Pennisetum purpureum, Azadirachta indica and Citrus limon during the survey conducted in 2023–24. This infestation of Aleurodicus rugioperculatus Martin with different host plants marks the first documented occurrence of this novel invasive whitefly species affecting India. These findings highlight the need for further research and management strategies to address the threats posed by this invasive pest.

Factors influencing adoption of agro-ecological pest management options for mango fruit fly under information constraints: a two-part fractional regression approach

The catalytic effect of climate change on the emergence and prevalence of invasive alien pests along with weak pesticide regulatory frameworks in developing countries calls for a transition towards sustainable pest management. Agro-ecological pest management (APM) offers a nature-based, cost-effective alternative for addressing systemic pest challenges, such as mango fruit fly invasion. We applied a two-part fractional regression to sequentially model APM adoption and intensity decisions among 423 smallholder mango orchard managers from Makueni County, Kenya. Despite APM’s potential, we observed moderate adoption rates (56.7%), with the average adopter implementing only 25% of the APM practices concurrently. Farmers’ socio-psychological attributes significantly influenced both adoption and intensity decisions. While perceptions of technology attributes and institutional and social factors primarily influenced both the adoption and intensity decisions, information constraints, resource endowment, gender and inter-generational factors significantly influenced only the intensity decision. To support the transition from synthetic insecticides to APM measures, policymakers should create more opportunities for awareness creation, training and knowledge co-creation and co-production, particularly through social networks and gender-disaggregated participatory group approaches.

A biosecurity perspective on urban trees in public and private spaces and trees available from nurseries

Urban trees are of high importance for healthy urban ecosystems. However, some trees are invasive plants that may ‘escape’ from urban areas into natural environments. Furthermore, invasive forest pests often arrive and establish in urban environments before they spread to forest ecosystems. Therefore, knowledge of tree species composition in urban areas is important for the biosecurity of cities and surrounding forests. Despite this, urban tree inventories often lack information on trees on private properties. To assess the potential role of urban areas as a source of invasive trees as well as invasive pests of trees, we compared the species composition of urban trees in public and private spaces in several Swiss cities and in tree nurseries (henceforth: ‘nurseries’) in Switzerland. We analysed the various data sets we compiled regarding invasive tree species, and examined how many trees are potential hosts for invasive quarantine pests of trees. We found no statistically significant difference in tree species composition in public and private urban areas, but the proportion of non-native trees was higher in private than in public spaces. Tree species available in nurseries and those present in cities were not significantly different, with larger urban tree inventories having a greater overlap with the species available in nurseries. Five of eight tree species considered invasive whose sale was banned since September 2024 were still on sale ten months before the ban came into force. All eight tree species were present in urban tree inventories. Importantly, between 91 % and 97 % of all urban trees in public and private spaces were suitable hosts for at least one quarantine forest pest. Given the pivotal role that urban trees play for the health of urban and peri-urban ecosystems, knowledge of tree species composition is essential from a biosecurity perspective. Our findings suggest that the combination of public urban tree inventories and trees available from nurseries can provide an estimate of the composition of private urban trees and can be useful for invasive species monitoring.

Loss-of-function in testis-specific serine/threonine protein kinase triggers male infertility in an invasive moth

Genetic biocontrol technologies present promising and eco-friendly strategies for the management of pest and insect-transmitted diseases. Although considerable advancements achieve in gene drive applications targeting mosquitoes, endeavors to combat agricultural pests have been somewhat restricted. Here, we identify that the testis-specific serine/threonine kinases (TSSKs) family is uniquely expressed in the testes of Cydia pomonella, a prominent global invasive species. We further generated male moths with disrupted the expression of TSSKs and those with TSSKs disrupted using RNA interference and CRISPR/Cas9 genetic editing techniques, resulting in significant disruptions in spermiogenesis, decreased sperm motility, and hindered development of eggs. Further explorations into the underlying post-transcriptional regulatory mechanisms reveales the involvement of lnc117962 as a competing endogenous RNA (ceRNA) for miR-3960, thereby regulating TSSKs. Notably, orchard trials demonstrates that the release of male strains can effectively suppress population growth. Our findings indicate that targeting TSSKs could serve as a feasible avenue for managing C. pomonella populations, offering significant insights and potential strategies for controlling invasive pests through genetic sterile insect technique (gSIT) technology.

Pre-emptive augmentative biological control of Spodoptera frugiperda in Europe using Trichogramma spp.

BackgroundFall armyworm, Spodoptera frugiperda, is a highly invasive pest of maize and other crops worldwide. It has recently been detected in Europe, and it is urgent to test and develop new sustainable control methods adapted to the European context and market. Trichogramma spp. are egg parasitoids that are sometimes used as biological control agent against S. frugiperda in other continents. However, a major issue using Trichogramma spp. against this pest is that females cannot reach all eggs in an egg mass, which is usually composed of one to three layers of eggs, often covered with scales and hair. Three European Trichogramma species were tested for their ability to parasitize egg masses with one to three layers and with or without hair and scale cover.MethodsTrichogramma brassicae, T. dendrolimi and T. cacoeciae were offered five types of S. frugiperda egg masses: one-layer without hair; one-layer with hair; two-layers without hair; two-layers with hair; three-layers with hair. For each treatment, an egg mass laid on paper was placed in a small vial saturated with females, to be sure that all reachable eggs would be parasitized. For each egg mass, the number of eggs in each layer was counted. Fifteen replicates were made per treatment, as well as 10 control vials without Trichogramma sp. Parasitism rates were calculated for each egg mass.ResultsThere were significant differences in the ability of parasitoid species to oviposit through hair and scales and to reach the lower egg layers. Trichogramma dendrolimi was the most efficient species and T. cacoeciae the least. Depending on the number of egg layers and hair and scales, parasitism rates by T. brassicae, T. dendrolimi and T. cacoeciae varied between 99 and 41%, 100 and 43% and 100 and 28%, respectively.ConclusionsThe assays confirmed that Trichogramma females cannot easily oviposit through thick layers of hair and scales but overall parasitism rates were higher than found previously. Important variations between species were found, and more Trichogramma sp. and other local natural enemies should be tested pre-emptively before S. frugiperda has invaded Europe.

Assessing the feasibility of pre-emptive biological control against the emerald ash borer, Agrilus planipennis, an imminent biosecurity threat to Europe

As the globalisation of trade increases, so does the spread of arthropod pests, leading to a growing focus on biosecurity preparedness. One approach to this is pre-emptive biological control, involving the importation of classical biological control (CBC) agents for risk assessments and acquiring approval for their release prior to the expected arrival of their target pests. This aims to mitigate the economic and/or environmental consequences of a delayed biological control response to pest invasions. Guidelines to assess the feasibility of pre-emptive biological control for high priority pests were recently developed. Emerald ash borer (EAB), Agrilus planipennis, is an invasive woodboring pest of ash (Fraxinus spp.) in North America, European Russia and Ukraine, and is spreading westward into Europe, threatening the future of European ash (Fraxinus excelsior). We applied the aforementioned guidelines to assess the feasibility of pre-emptive biological control in Europe using four EAB parasitoids, already released in North America for CBC. Three of the parasitoids; Oobius agrili, Spathius galinae, and Tetrastichus planipennisi, were found suitable for pre-emptive biological control. The fourth parasitoid, Spathius agrili, was found to have limited establishment in new environmental conditions, and was therefore deemed less suitable for pre-emptive biological control of EAB in Europe. This assessment can inform scientists and regulators in Europe on the most promising EAB parasitoids that should be considered for pre-emptive applications for importation and risk assessment to acquire pre-approval for immediate release should the target pest subsequently be discovered. In turn, this study contributes to the development of biosecurity preparedness against EAB’s imminent spread throughout Europe.

Carvacrol acts on the larval midgut of Spodoptera frugiperda by destroying the tissue structure and altering the bacterial community

The fall armyworm, Spodoptera frugiperda, has become a global invasive pest in recent years, threatening agricultural production. Carvacrol (CAR) is a multifunctional plant-derived compound and exhibited significant bioactivities against many pests. Our previous study found that CAR inhibited growth and development in S. frugiperda. However, the effects of CAR on the midgut of this pest remain unknown. In this study, the actions of CAR on the larval midgut of S. frugiperda were investigated. The results found that 1.0 and 2.0 g/kg CAR treatments destroyed the structure of the larval midgut based on hematoxylin-eosin staining and transmission electron microscope observation. In addition, 2.0 g/kg CAR exposure significantly altered the larval midgut bacterial community composition and structure. The results of the linear discriminant analysis effect size (LEfSe) analysis suggest that six bacterial genera contributed to the different structures of the larval bacterial community. Furthermore, PICRUSt2 analysis found that 16 bacterial function categories were altered by CAR treatment, of which 8 were significantly increased. Our results provided new insight into the toxicological mechanisms of CAR against S. frugiperda larvae and laid the foundation for the field application of S. frugiperda control.

Potential distribution of Acerophagus papayae, a parasitoid of the papaya mealybug (Paracoccus marginatus), across Africa

The papaya mealybug, Paracoccus marginatus, is a highly polyphagous invasive pest that affects at least 133 economically important crops, and causes economic losses worldwide. Acerophagus papayae (Noyes and Schauff), a parasitic wasp, has proven to be a successful biocontrol agent, but its use in Africa is limited. Here, we use a predictive correlative model to explore the potential distribution of A. papayae and relate it to data showing the potential distribution of P. marginatus, to highlight potentially suitable areas for biological control of P. marginatus, for its current distribution, as well as its potential future distribution.The resulting model performed well with a test AUC of 0.89. Areas that were highly suitable for P. marginatus and were also suitable for A. papayae were highest across West Africa. Whilst there were areas which were suitable for both species in both East Africa and Central Africa, there were large areas of cropping land which were highly suitable for P. marginatus although not suitable for A. papayae. Across Northern and Southern Africa, there were limited cropping areas which were suitable for P. marginatus and where there was suitability, it was only moderate. Across these areas, there was limited suitability for A. papayae.Our results offer refined information on the potential suitability for A. papayae across Africa with the aim to help guide decisions on the areas where use of A. papayae could be used effectively as a part of an integrated pest management programme against P. marginatus.

A potential trade-off between reproduction and enhancement of thermotolerance in Liriomyza trifolii populations driven by thermal acclimation

The invasive pest, Liriomyza trifolii, poses a significant threat to ornamental and vegetable plants. It spreads rapidly and causes large-scale outbreaks with pronounced thermotolerance. In this study, we developed L. trifolii strains adapted to high temperatures (strains designated 35 and 40); these were generated from a susceptible strain (designated S) by long-term thermal acclimation to 35 °C and 40 °C, respectively. Age-stage, two-sex life tables, thermal preferences, critical thermal limits, knockdown behaviors, eclosion and survival rates as well as expression of genes encoding heat shock proteins (Hsps) were compared for the three strains. Our findings indicated that the thermotolerance of L. trifolii was enhanced after long-term thermal acclimation, which suggested an adaptive plastic response to thermal stress. A trade-off between reproduction and thermotolerance was observed under thermal stress, potentially improving survival of the population and fostering adaptionary changes. Acclimation at 35 °C improved reproductive performance and population density of L. trifolii, particularly by enhancing the fecundity of female adults and accelerating the speed of development. Although the 40 strain exhibited the highest developmental speed and greater thermotolerance, it incurred a larger reproductive cost. This study provides a theoretical framework for monitoring and controlling leafminers and understanding their evolutionary adaptation to environmental changes.

Symbiont community assembly shaped by insecticide exposure and feedback on insecticide resistance of Spodoptera frugiperda

Exploring the mechanism of microbiota assembly and its ecological consequences is crucial for connecting microbiome variation to ecosystem function. However, the influencing factors underlying microbiota assembly in the host-microbe system and their impact on the host phenotype remain unclear. Through investigating the prevalent and worsening ecological phenomenon of insecticide resistance in global agriculture, we found that insecticide exposure significantly changed the gut microbiota assembly patterns of a major agricultural invasive insect pest, Spodoptera frugiperda. The relative importance of various microbiota assembly processes significantly varied with habitat heterogeneity and heterogeneous selection serving as a potential predictor of the host’s insecticide resistance in field populations. Moreover, disturbance of the gut microbiota assembly through antibiotics was revealed to significantly affect the rate and heritability of insecticide resistance evolution, leading to a delay in insecticide resistance evolution in this insect pest. These findings indicate that the gut microbiota assembly process of the insect host is influenced by persistent exposure to habitat conditions, particularly insecticides. This variation in insecticide exposure-related community assembly process subsequently influences the insect host’s insecticide resistance phenotype. This study provides insights into gut microbiota assembly processes from a symbiotic perspective and underscores the significant impact of symbiotic community changes on host phenotypic variation.

Strengthening plant health systems in South Sudan: addressing challenges and enhancing system efficiency and sustainability

Climate change-induced invasive pests remain a major bottleneck to agricultural productivity and food security in South Sudan. Strengthening the plant health system has the potential to contribute to reducing crop losses caused by pests. A situational analysis was conducted to assess the current state and effectiveness of plant health functions in three counties in South Sudan. Descriptive findings of data collected from 960 farmers in Juba, Yambio, and Yei indicated low access to plant health services, including advisory and extension, training, and information. There was a high dependence on NGOs and UN agencies to provide plant health services, indicating a gap in government-led initiatives. The findings demonstrate a complex relationship between plant health services and on-farm practices and regional variations in access to plant health services and resources. The findings have crucial implications for the plant health system in South Sudan, requiring the need for service accessibility, government involvement in plant health systems, strengthening of the policy and regulatory frameworks, and inclusivity in service provision.